Characterization of HbA1c Levels in a Subsample of Hispanic Adults Living in the San Juan Metropolitan Area

Abstract

Objective: To determine the mean levels of glycated hemoglobin (HbA1c) in a subsample of non-diabetic Hispanic Puerto Ricans living in the San Juan metropolitan area (SJMA) and to assess the sensitivity and specificity of HbA1c as a diagnostic test for prediabetes. Research design and Methods: This was a secondary data analysis of the parent study, Burden of Diabetes and Hypertension in the Adult Population of the San Juan Metropolitan Area of Puerto Rico. Based on their HbA1c and fasting plasma glucose (FPG) values, 370 adults (147 males; 223 females) were classified as non-diabetics. An additional analysis of sensitivity, specificity, and predictive values for this subsample examined the association between FPG and HbA1c. Results: The mean HbA1c among the non-diabetic population was 5.38% (±0.23). Sensitivity, specificity, and the area under the receiving operating characteristic curve were 56.8%, 74.2%, and 84.3%, respectively, for the diagnosis of prediabetes, using HbA1c as the sole diagnostic test (P<0.001). Conclusion: This study demonstrated that HbA1c levels among the non-diabetic Hispanic population residing in the SJMA were very similar to those of non-Hispanic whites living in the US. Our results are consistent with those of other studies that have shown that the sensitivity of the HbA1c test is too low to be used in the diagnosis of prediabetes.